Lasing dye and method of preparation

ABSTRACT

4-Trifluoromethyl-7-hydroxycoumarin is prepared and disclosed as being useful as a lasing dye in the green to blue-green regions.

United States Patent [191 Long et a] 260/3432 Hammond Dec. 16, 1975 LASING DYE AND METHOD OF 2,680,747 6/1954 Williams et a1. 260/3432 PREPARATION 3,521,187 7/1970 Snavely et a! 260/3432 [75] Inventor: getle; R. Hammond, China Lake, OTHER PUBLICATIONS a 1 [73] Assignees: Peter R. Hammond, China Lake, 52 synthesls" 21 (1941) Calif; The United States of America as represented by the Secretary of a the Navy, Washington, DC. Primary ExaminerJames A. Patten Attorney, Agent, or FirmR. S. Sciascia; Roy Miller; [22] Flled. Nov. 25, 1974 Lloyd E. K. Pohl [2i] Appl. No.: 526,760

52 US. Cl. 260/3432 R; 331/945 [57] ABSTRACT Int. GL2 4 Trifluorometh l 7 h d d d yy roxycoumann 1s prepare an Fleld of Search R disclosed as being useful as a lasing y in the green to bl Y [56] References Cited ue green reglons UNITED STATES PATENTS 3 Claims, No Drawings LASING DYE AND METHOD OF PREPARATION BACKGROUND OF THE INVENTION However, to the best of the inventor's knowledge, the

coumarin disclosed herein has never been prepared before. Naturally, since the inventor has no knowledge of the herein disclosed compounds preparation, the inventor also has no knowledge of any previous disclosure of the compounds usefulness as a lasing dye.

SUMMARY OF THE INVENTION The compound disclosed herein is 4-trifiuoromethyl- '7-hydroxycoumarin. It is prepared by reacting resorcinol and ethyl 4,4,4-trifluoroacetoacetate.

DESCRIPTION OF THE PREFERRED EMBODIMENT 4-Trifluoromethyl-7-hydroxycoumarin may be prepared according to the following example:

EXAMPLE 1 Resorcinol (5.5g. /.05 mole) and ethyl 4,4,4-trifluoroacetoacetate (9.2g./.05 mole) were dissolved in 20 ml of dry benzene. Phosphoryl chloride catalyst (2 ml) was added. The reaction mixture was refluxed for 5 hours and then allowed to cool to room temperature. The solid reaction product was filtered from the reaction mixture and recrystallized from a 50-50 by volume dioxane-water mixture. The thus recrystallized product proved to be, upon NMR and elemental analysis, 4-trifluoromethyl-7-hydroxycoumarin.

Anal: Calcd. C 52.2, H 2.18, F 24.8; Found, C 52.4, H 2.27, F 25.00. Melting point 183.0 to 184.0C.

Testing of 4-trifluoromethyl-7-hydroxycoumarin for its lasting properties was carried out according to the following example:

EXAMPLE 2 Enough 4-trifluoromethyl-7-hydroxycoumarin to form a 10 molar solution was placed in water and the water was slowly heated to ensure complete solution. After heating for a few minutes, the solution was allowed to cool to room temperature. A portion of the 10 molar solution was then placed in an Avco-Eve rett Dial-a-Line nitrogen laser and was found to lase in the green region.

4-Trifluoromethyl-7-hydroxycoumarin can be made to lase in the blue-green region as well as the green by tuning with the aid of a diffraction grating.

What is claimed is:

1. 4-Trif1uoromethyl-7-hydroxycoumarin.

2. A method for preparing 4-trifluoromethyl-7- hydroxycoumarin comprising the steps of:

a. dissolving equimolar amounts of resorcinol and ethyl 4,4,4-trifluoroacetoacetate in dry benzene;

b. adding phosphoryl chloride catalyst; and

c. refluxing.

3. The method according to claim 2 wherein the refluxing step is carried out for 5 hours. 

1. 4-TRIFLOUROMETHYL-7-HYDROXYCOUMARIN.
 2. A method for preparing 4-trifluoromethyl-7-hydroxycoumarin comprising the steps of: A. DISSOLVING EQUIMOLAR AMOUNTS OF RESORCINOL AND ETHYL 4,4,4-TRIFLUOROACETOACETATE IN DRY BENZENE; B. ADDING PHOSPHORYL CHLORIDE CATALYST; AND C. REFLUXING.
 3. The method according to claim 2 wherein the refluxing step is carried out for 5 hours. 